This invention relates to sustained release compositions and products produced therefrom. More specifically, it relates to compositions and products comprising active substance depots dispersed in a flexible carrier suitably an adhesive or a polymeric foam. Still more specifically, and by way of example, it relates to cleaning products and compositions which slowly release a detergent over an extended period of time during use.
For ease of description, but without limitation, the products of this invention will be described principally as cleaning products. Those skilled in the art, however, will immediately appreciate that the concept and applicability of the invention is not limited to such products.
The preparation of cleaning products such as textiles, papers and foam sponges containing polishing or abrasive agents or covered with a layer of such materials is well known. These products are used for various purposes, such as household cleaning.
Additionally, attempts have been made to include certain active agents such as soaps, in the cleaning product to increase the cleaning effect. It has been observed, however, that these active substances are washed out and used up or lost within a very short period of use. The initial advantages of the products are, therefore, rapidly dissipated. Accordingly, the art has long been concerned with the production of products containing active substances which can be readily and economically produced, and which will retain their initial advantages over an extended period of time.
One such product is described in U.S. Pat. No. 3,334,374. In accordance with the invention described in that patent, pressure rupturable capsules, which may be regarded as analogous to the active substance depots of this invention, are contained within flexible, sealed receptacles. Such receptacles include, for example, thin, flat pouches with front and back walls sealed along their peripheral edges. The capsules are loosely contained within the receptacles. Such products are not completely satisfactory for a number of reasons, and have not found wide commercial acceptance.